Drosophila melanogaster grooming possesses syntax with distinct rules at different temporal scales
Fig 10
A nonstationary Markov renewal process recapitulates grooming progression and bout structure.
A: Illustration of the time-varying transition matrix, M(t), used for generating synthetic ethograms. To approximate changing sensory conditions in the simplest possible manner, two transition matrices, Mearly and Mlate, are fit to the first and last 200 actions in the discrete time ethogram with 3 duration categories, respectively. As time evolves in the synthetic ethogram simulation, M(t) changes as described in Eq 6. At the beginning of the simulation, M(t) is identical to Mearly and after 13 minutes, it is identical to Mlate. Between those times, it is a linear combination of the two matrices. B: Synthetic ethograms display the characteristic progression from anterior to posterior grooming, as seen from comparison with Fig 5. C: Synthetic ethograms reproduce observed anterior motif composition. Synthetic anterior motifs (left) exhibit a similar, though slightly weaker, trend as observed in our data (Fig 6). Posterior motifs are less similar, indicating that other factors may be necessary to explain posterior motif structure.